It's Bat Sentry Unit 2! This ti8me with light-up shoulders and chest symbol. I'd make the eyes light up but I need a different head as this one is soft plastic. The chest emblem rotates to the light-up symbol, regular bat symbol, Unit 02, and a battle-damaged bat symbol. It's made from the Shadowtek Electronic Batman twin-blaster figure that I snagged a bunch of on sale.
Opening up the body is easy, getting the shoulders open is hard! You have to saw through 4 connector rods. I then carved through the shoulder grating and made 'epoxy glass' to fill in there. Once that was done I had to carve through one of the chest symbols. Installing a 3-LED light unit inside the body took 3 hours of drilling ports, wiring/soldering, and figuring out how to keep the center section turning without snagging the wires. It was a real pain but hey, it worked!